Interview with Diederik Hellingh and Katrien Gentens from GC
EUROPE on a new helpful booklet:
Guidelines for the correct use of PBIs:
“Focus Edition” helps to find solutions
A guideline for optimal use and a troubleshooting list –
these items will help dental technicians to get the most out
of GC EUROPE's Phosphate Bonded Investment materials.
The new brochure called “Focus Edition” provides detailed
instructions for the optimal techniques when working with
GC's high quality products for crown and bridge technique.
We spoke to Diederik Hellingh, Laboratory Products
Manager, and Katrien Gentens from R&D/QC Department
who explained why this document can help technicians
avoid mistakes and potential problems in the future.
Please explain the “Focus Edition” in short words?
Hellingh: The idea behind the “Focus Edition“ is to offer our
dedicated customers an informative document on the use of our
products. In fact this edition offers a “focus” on the main criteria
when using our products – a guideline for optimal use. We hope
that reading this document helps to improve our (future)
customers' understanding of GC EUROPE phosphate bonded
investment materials in a practical and relevant manner that is
beneficial to their daily „Crown & Bridgework‟ practice.
What is the aim of this new supportive tool?
Hellingh: When using phosphate bonded investments there are
multiple factors influencing the final result: differences in use of
materials (wax, resins, alloy types…), differences in techniques
(fast heating, ringless technique…) and environmental
influences like temperature and of course the human factor. The
aim of this document is to help understand our products in more
detail and provide useful information that will help to avoid
mistakes and potential problems in the future, by identifying the
optimal techniques for their use and by analysing the various
problems that can occur if „best practice‟ is not followed.
Gentens: We also integrated a part called “Troubleshooting”,
were we offer solutions to the possible problems encountered
during the use of PBIs, by analysing the cause and offering a
Which influence did the technicians or KOL have on the
“Focus Edition”? And do you systematically survey
Hellingh: It is of key importance we stick to reality, so we are
indeed in close contact with our customers in general.
Gentens: Our numerous in-house tests and years of experience
offer a very profound knowledge of the chemistry and behaviour
of investments. We work with external consultants all over
Europe on a regular basis in order to get the best information on
the behaviour of our investments in “real” circumstances.
What properties in a phosphate bonded investment are in
general important to you?
Hellingh: Of course we create products that meet the needs of
our dedicated customers and in general they highly appreciate
reproducibility, robustness and precision when using
Gentens: That‟s why we use highly refined raw materials. Our
production follows strict processes and we implement multiple
quality controls before materials are released on the market.
What do you think are the typical sources of error in
investment working? And how can they be avoided?
Hellingh: Customers expect a reproducibility of good results
from their investment. In order to get this it is of importance that
the way of working for each indication (type of work) is constant
and similar, each time. In many cases there is not a real
“protocol” and this could lead to differences in end-results.
Gentens: A typical source of error is mostly time related,
meaning that due to the time pressure in the dental lab, the
setting process is disturbed by e.g. heating up the furnace too
early or a premature removal of the silicone. This disturbance in
the chemical process during hardening can lead to miscasting.
So we advise to keep to a standardized way of working.
How important is a temperature controlled refrigerator and
an atomized measuring equipment for consistent results?
Hellingh: The use of a temperature controlled refrigerator set at
21-23°C is highly recommended for the storage of the
investment powder, liquid and mixing vessels, as this
completely eliminates the risk of seasonal temperature
Gentens: In order to obtain consistently accurate castings the
correct powder/liquid ratio must be used, as this ratio is the
result of comprehensive laboratory development and batch
testing. Any alteration of the ratio is likely to result in less
predictable expansion properties, an inferior casting surface and
an increased risk of mould fracture. The use of an accurate
electronic balance for weighing the powder together with a
measuring cylinder or pipette for the liquid is highly
What are the key advantages of using GC investment
Hellingh: GC Investments presents highly specialized
investments for each indication offering reproducibility,
robustness and ease of use. We have years of experience
manufacturing investments and have a highly skilled sales force
offering advice to their customers.
GC Fujivest Premium and Platinum are both multi-purpose
investment materials, does this mean the technicians have
to make a lot of compromises regarding precise castings
and smooth surfaces?
Hellingh: GC Fujivest Platinum and Premium can be
considered as complementary: Platinum is a specialist for high
precision precious castings and Premium is a specialist for the
Non precious precision castings.
Gentens: Both are highly refined modern investment types
whereas Platinum’s focus is on the surface smoothness and
precision for precious alloys. The focus of Premium is on the
wide expansion range and robustness for all techniques for the
use of non-precious alloys.
Hellingh: When customers are looking for a universal type of
investment for the all round type of work, then GC Fujivest
Premium is the preferred choice.
One final question: Which research results do you expect
to have an influence in upcoming product developments?
In fine: What do you think the future holds for investment
Hellingh: In the current situation of trendy CAD/CAM evolution
it is obvious that technicians will use less investment and spend
less time on the actual understanding of the material.
Technicians expect to have ready to use materials that are
reproducible and less time consuming. Our job is to offer our
customers these investments offering them a “perfect fit”!
Gentens: With the publishing of the “Focus Edition” on PBIs, we
hope the technicians will benefit from the information
illustrations and find fulfilment in achieving the perfect fit of a
cast metal restoration, even in the current, ever-present
Thank you very much for this interview.